Inline filter having swivel fitting

ABSTRACT

An inline filter having a swivel right-angle fitting for coupling an inlet or outlet tube. The fitting includes a stem having a pair of O-rings and a distal ridge and notch. The cap of the filter includes a port having a plurality of annular, resilient tabs that engage the notch and ridge to retain the fitting to the cap.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.08/612,981 filed Mar. 1, 1996, now U.S. Pat. No. 5,882,515.

TECHNICAL FIELD

The invention relates generally to filters and more particularly toinline filters having a swivel fitting on at least one end.

BACKGROUND ART

Filters are commonly used to purify liquids such as water. Inlinefilters, which have an inlet at one end out an outlet at the other, areconvenient for many different filter applications.

An inline filter, in its simplest form, is merely a hollow vesselholding a filtration medium that has an inlet port at one end and anoutlet port at the other end. Typically, associated with the inlet andoutput ports are fittings for connecting supply and drain tubing.

A common fitting is a “right-angle” fitting that allows the supply anddrain tubing to connect to the inlet and outlet ports at right angles tothe axis of the tubing, facilitating a compact or convenient tubingarrangement in certain applications. Prior filters have included rightangle fittings integral to their ports. Unfortunately, constructing aninline filter with right-angle fittings as integral with the ports fixestheir coupling angles.

If such a filter has a circular cross section, then it may be possiblefor the entire filter to be rotated within its mounting to adjust thecoupling angles of the fittings. However, rotating the filter causesboth fittings rotate the same angle. There is no way to adjust theradial coupling angles of the fittings with respect to each other.

What is needed is a filter construction that allows for independentadjustment of the radial angles of right-angle fittings for inlinefilters.

DISCLOSURE OF THE INVENTION

It is therefore an object of the present invention to provide an inlinefilter that has right-angle fittings that can rotate independently ofeach other and independently of the filter body.

According to the present invention, the foregoing and other objects andadvantages are attained by a filter design and right-angle fittingdesign which enables the right-angle fittings to rotate with respect tothe filter body while maintaining a leak-proof seal.

As an advantage of the present invention, maximum flexibility andadjustability in the routing of source and drain tubing is achieved.

These and other features, advantages, and objects of the presentinvention will become apparent to those skilled in the art uponexamination of the following specification when taken in conjunctionwith the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a filter constructed according to thepresent invention having two swivel right-angle fittings.

FIG. 2 is a front elevation view of the filter of FIG. 1.

FIG. 3 is a side elevation view of the filter of FIG. 1.

FIG. 4 is a sectional view of the filter, taken along line 4—4 of FIG.2.

FIG. 4A is a sectional view of the filter, taken along line 4A—4A ofFIG. 4.

FIG. 5 is an expanded sectional view of the filter of FIG. 4, beforefinal assembly, with the filtration medium removed for clarity.

FIG. 5A is a perspective view of a deflector.

FIG. 6 is an enlarged sectional view of one end of the filter having aswivel right-angle fitting with a quick disconnect coupling.

FIG. 7 is an enlarged sectional view of a swivel right-angle fittingwith a taper threaded coupling.

FIG. 8 is a sectional view of one end of a filter having an integralright-angle fitting with a quick disconnect coupling.

FIG. 9 is a sectional view of one end of the filter having an integralright-angle fitting with a taper threaded coupling.

FIG. 10 is an exploded elevational view, partially in section, of oneend of a reverse osmosis filter having a swivel right-angle fitting andan integral brine fitting.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and with particular reference to FIGS. 1through 3, an exemplary inline filter 20 according to the presentinvention comprises a hollow body 22 having an integrally-formed cap 24at its lower end and a spin-welded cap 26 at its upper end. (“Upper” and“lower” are used for convenience in referring to elements of the filterin the drawings and not to indicate required orientations of the filter20 during use.) Attached to both caps 24, 26 are respective right-angleswivel fittings 28, 30. The fittings 28, 30 couple to inlet and outlettubing (not shown). Water from the inlet tubing passes through thefilter 20 and is filtered thereby before exiting out the outlet tubing.

Referring now to FIGS. 4 and 5, the filter 20 comprises five maincomponents: the body 22, the cap 26, the swivel right-angle fittings 28,30, and a deflector 32. These components are made from polypropylene,acrylonitrile butadine styrene (ABS), or another suitable plasticmaterial. If the filter 20 is to be used to filter potable water, thefilter material should be approved for such use. In an exemplary filter20, these main components are manufactured using an injection moldingprocess.

Referring to FIGS. 4, 4A, and 5, the filter body 22 has a cylindricalwall 34 defining an interior media chamber 35 that has a circular crosssection. In a first exemplary filter 20, the media chamber 35 has adiameter of 1.5 inches (38.1 mm). In a second exemplary filter 20, themedia chamber 35 has a diameter of 2.0 inches (50.8 mm). The wall 34has-a thickness of 0.25 inches (6.35 mm), resulting in outside diametersfor the first and second exemplary filters of 2.0 inches (50.8 mm) and2.5 inches (63.5 mm), respectively. For both exemplary filters, themedia chamber 35 is 13 inches (330.2 mm) long. It should be recognizedthat an inline filter can have shapes and dimensions other than thosedescribed above without departing from the spirit of the presentinvention.

The body 22 is sealed at one end by the integrally-formed cap 24 havinga port 36 therethrough. Referring to FIGS. 4A and 5, surrounding port 36and within the interior of body 22 is a cylindrical cup 38. Foursemicircular notches 39 are evenly spaced on the top edge of the cup 38.

Adjacent to the cup 38, a plurality of narrow fins 40 are spacedradially about the interior if cylindrical wall 34. A lower ledge 42 isformed on the inside of wall 34. The top edges of the cup 38, the fins40, and the ledge 42 meet at a common plane. A disc of felt 44 issonically welded to the cup 38, the fins 40, and the ledge 42 on thisplane. The diameter of the felt disc 44 matches the inside diameter ofthe wall 34 at the lower ledge 42. In an exemplary embodiment of thefilter 20, the felt disc 44 is 0.125 in (3.175 mm) thick and is madefrom polypropylene with 20 micron nominally rated pore sizes.

At the upper end of the filter body 22 is a cylindrical spin weld ledge46, or “interference point,” surrounded by a cylindrical shield 48. Thewall 34 also includes an upper ledge 50.

Referring now to FIG. 5A, the deflector 32 comprises a circular outerring 52, a circular inner disk 54, and radial arms 56, all formed as anintegral whole. In an exemplary filter 20, the deflector is 0.125 inch(3.175 mm) high, the outer ring 52 and radial arms are 0.125 inch (3.175mm) wide, and the inner disk is 0.5 inch (12.7 mm) in diameter. Theouter diameter of the deflector 32 is sized to fit snugly against theinterior surface of the cylindrical wall 34 at the upper ledge 50.

Referring again to FIG. 5, the cap 26 includes a substantially planarportion 62 having a port 64 therethrough. Around the perimeter of theport 64 are a plurality of resilient tabs 66 separated by slots 68.Around the perimeter of the cap 26 is a lip 70. Projecting substantiallyperpendicular from the planar portion 62 is a cylindrical spin weld tail72. In an exemplary embodiment, the outer diameter of the spin weld tail72 is 2.130 inches (54.10 mm); the inner diameter of the spin weld ledge46 steps from 2.158 inches (54.81 mm), to 2.125 inches (53.98 mm), andthen to 2.100 inches (53.34 m).

During assembly, the lower felt disc 44 is sonically welded to the upperedges of the fins 40, the cup 38, and the lower ledge 42. The mediachamber 35 is then filled with a selected filtration media 60, such asgranulated activated carbon. A second disc of felt 58, similar inmaterial to the first felt disk 44 and having the same diameter asdeflector 32, is sonically welded to the lower surface of the deflector32. Then the deflector-felt disc unit is placed in the filter 20 withits felt side against the per ledge 50. The two felt discs 44, 58contain the filtration medium 60 within the filter body 22.

The cap 26 and body 22 are joined in a process known as “spin welding.”The spin weld tail 72 of the cap 26 is forced against the spin weldledge 46 of the body 22 and rotated at high torque about their commonaxis. Friction between the spin weld tail 72 and the spin weld ledge 46generates heat that softens and melts them both, melding their adjacentsurfaces together. The cap 26 is further rotated and forced into thebody 22 until the upper surface of the cap 26 is flush with the uppersurface of the shield 48, as shown in FIG. 4. The deflector 32 preventsany molten plastic from leaking into the media chamber 35.

Referring now to FIGS. 6 and 7, a right-angle fitting 28 comprises ahead portion 74 and a cylindrical stem portion 76. A passage 78 throughthe stem portion 76 is in communication with a coupling 80. The coupling80 couples a tubing to the fitting 28 perpendicular to the axis of thestem portion 76. The coupling 80 can be a taper threaded coupling asshown in FIG. 7, or a quick-disconnect type, which uses a collet, acollar, and an O-ring (not shown) to couple a tubing to the fitting 74,as shown in FIG. 6. Alternatively, the fitting 28 may use some othertype of coupling.

The stem portion 76 includes two annular grooves 82 sized to retainrespective rubber O-rings 84. The outer diameter of the stem portion 76is slightly smaller than the inner diameter of the port 36 such that,with the O-rings 84, a water-tight seal is formed between the fitting 28and caps 24, 26. Furthermore, the fitting 28 can rotate about the axisof the stem portion 76 while retaining the seal.

At the end of the stem portion 76 is a ridge 84 adjacent to an annularnotch 86. When the stem portion 76 of the fitting 28 is pushed into theport 36, the tabs 66 flex to allow the angled ridge 84 to pass betweenthe tabs 66. After the fitting 28 has traveled sufficiently far, thetabs 66 snap into engagement with the notch 86 and prevent the fitting28 from being removed from the port 36. During use of the filter 20,internal water pressure on the tabs 66 increases their grasp on notch 86and ridge 84.

Referring again to FIGS. 1 through 3, an inline filter according to thepresent invention includes at least one swivel right-angle fitting; thefilter 20 shown in FIGS. 1 through 7 has two swivel right-angle fittings28, 30. These fittings 28, 30 can rotate independent of each other andindependently of the filter body 22, allowing for maximum flexibilityand simplicity in the routing of source and drain tubing (not shown).

Referring again to FIG. 4, when in use, water enters the filter 20through the upper swivel right-angle fitting 30. The water passesthrough the open spaces of the deflector 32 and then through the upperfelt disc 50 into the filtration medium 60. Next, the water passesthrough the lower felt disc 44. Water passing through the center regionof the lower felt disc 44 directly enters the cup 38; water passingthrough the outer regions of the lower felt disc 44 enters the cupthrough the four semicircular notches 39. The now-filtered water exitsthe filter 20 through the lower swivel right-angle fitting 28.

Referring now to FIGS. 8 and 9, one of the caps 24, 26 may include anintegral fitting 90. FIG. 8 shows a right-angle fitting 90 having aquick-disconnect coupling 80, and being integral with theintegrally-formed cap 24. The right-angle fitting 90 of FIG. 9 has ataper threaded coupling 80. When used in conjunction with a filtermounting (not shown) that allows the filter body 22 to be rotated, thefilters of FIGS. 8 and 9 that have only one right angle fitting thatswivels can still independently adjust the desired angles of both rightangle fittings 30, 90.

Referring now to FIG. 10, a swivel fitting 92 can be used in a reverseosmosis filter 94 that has a brine port 96. The swivel fitting 92connects to the filter 94 in the same manner described above. A reverseosmosis membrane (not shown) is pressed into the cup 98.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized the scope of theinvention is defined and limited only by the claims which follow.

What is claimed is:
 1. An inline water filter, comprising: a generallycylindrical filter body having a first end and a second end and alongitudinal axis, said filter body defining a hollow interior anddefining openings at each of said ends, said openings being incommunication with said interior; a first cap attached to said filterbody at said first end and sealing said opening at said first end, saidfirst cap defining a circular port having annular resilient tabs; asecond cap integral with said filter body at said second end, saidsecond cap sealing said opening at said second end; a firstsubstantially right-angle fitting having a cylindrical stem portion withan annular ridge engaging said annular resilient tabs of said first cap,said first fitting configured to connect a first tube to said filter,said first fitting being rotatable about the longitudinal axis; a secondsubstantially right-angle fitting attached to said second cap, saidsecond fitting configured to connect a second tube to said filter; and aquantity of a granulated activated carbon filtration media inside saidfilter body.
 2. The inline filter of claim 1, further comprising anannular O-ring surrounding said stem portion of said first right-anglefitting and being interposed between said stem portion and said port ofsaid first cap.
 3. A The inline filter of claim 1, wherein said secondcap defines a second circular port having a second plurality of annularresilient tabs, and wherein said second right-angle fitting has a secondcylindrical stem portion with a second annular ridge engaging saidsecond plurality of annular resilient tabs of said second circular port.4. The inline filter of claim 3, further comprising a second annularO-ring surrounding said second stem portion of said second right-anglefitting and being interposed between said second stem portion and saidsecond port of said second cap.
 5. The inline water filter of claim 1wherein the longitudinal axis about which said first fitting isrotatable is a central axis of the generally cylindrical filter body. 6.The inline water filter of claim 1 wherein the first cap is spin weldedto said filter body.
 7. The inline water filter of claim 1 and furthercomprising a cylindrical cup surrounding the circular port within thehollow interior of the filter body.
 8. The inline water filter of claim1 and further comprising a porous filter disc separating the activatedcarbon filtration media and the circular port.
 9. The inline filter ofclaim 1 and further comprising a brine port structure molded into one ofthe first and second caps for alternate use of the filter body with areverse osmosis membrane.
 10. The inline filter of claim 1 wherein thesecond right-angle fitting is integrally molded into the second cap. 11.An inline water filter, comprising: an elongated generally tubularfilter body defining a hollow interior; a first end cap attached to afirst end of said filter body, the first end cap defining a port; asecond end cap integrally formed with a second end of said filter body;a first substantially right-angle fitting attached to said first endcap, said first fitting communicating with the hollow interior of thefilter body and having a first hollow stem portion that extends intosaid port and a second hollow head portion configured to connect to afirst tube, the stem portion being rotatable about a longitudinal axis,and the first end cap having a plurality of resilient tabs surroundingthe port that engage a ridge on the stem portion of the first fitting;at least one O-ring surrounding the stem portion of the first fittingand providing a water tight seal between the stem portion and theportion of the first cap defining the port; a second fitting integrallyformed with said second cap, said second fitting communicating with thehollow interior of the filter body and being configured to connect to asecond tube; a filtration medium inside said filter body; porous meansfor separating the filtration medium and the port of the first end cap;wherein unfiltered liquid enters said filter body through one of saidfirst and second fittings and filtered liquid exits said filter bodythrough another of said first and second fittings after passing throughboth the filtration medium and the porous means; and whereby relativerotation of said first substantially right angle fitting and said filterbody allows for adjustment of a radial angle between said first andsecond fittings to permit flexibility of routing said first tube andsaid second tube.